In industrialized countries, such as in the United States, there are vast quantities of low-temperature heat energy which are dissipated uselessly into the environment. This low-temperature heat energy is contained in gases, liquids, and solids, which are discharged from industrial plants at temperature levels currently considered to be too low for the heat energy therein to be economically utilized.
Also, throughout many geographic areas of the world, a radiation absorbent heat exchanger such as one having a dull black surface and which is insulated against heat loss, can be heated to temperatures of 250.degree. F. or more by solar radiation. Although such solar radiation-heated heat exchangers are currently being utilized for purposes of heating buildings, houses and other inhabited spaces, they are not currently used very much for recovery of solar energy in a form suitable for performing useful mechanical work, for example such as to generate electrical power or to drive machinery or for conversion into an energy form suitable for long term storage. Thus, much of the incident solar energy in the world is currently allowed to become dissipated to the environment as waste heat energy.
The present invention provides method and apparatus for converting into useful mechanical work such low-temperature industrial and solar heat energy and other waste heat energy which is now being dissipated to ambient.